1. Field of the Invention
The present invention relates to a transporting rail unit including a rail designed to guide the movement of an object and a driving mechanism generating a driving force for driving the object to a predetermined position on the rail. In particular, the present invention relates to a transporting rail unit preferably utilized in a transporting mechanism unit including a chain belt put on a pair of sprockets, a rail extending in parallel with the chain belt in a space between the sprockets, and a carriage guided on the rail for relative movement.
2. Description of the Prior Art
A so-called magnetic tape library apparatus is well known. The magnetic tape library apparatus includes a main cabinet containing magnetic tape drives and cell boxes. The cell box includes cells each capable of holding a magnetic tape cartridge. The magnetic tape cartridges are individually transported between the cell box and the magnetic tape drive. The magnetic tape drive is capable of recording magnetic information data in the magnetic tape cartridge, for example.
An extension cabinet can be coupled to the main cabinet. Cell boxes are likewise contained in the extension cabinet. A magnetic tape cartridge is transferred from the cell box in the extension cabinet to the magnetic tape drive in the main cabinet. A so-called pass-through mechanism, namely a transporting rail unit, is attached across the main cabinet and the extension cabinet. A carriage is allowed to reciprocate on the rail in the transporting rail unit between the main cabinet and the extension cabinet.
A conventional magnetic tape library apparatus requires different transporting rail units depending on the number of additional extension cabinets. Specifically, several kinds of transporting rail units having different lengths need to be prepared depending on the number of the additional extension cabinets. This results in an inevitable increase in the production cost and the management cost.